Runway incursions are dangerous events at airports. Runway incursions involve an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in a loss of separation with an aircraft taking off, intending to take off, landing, or intending to land. 60% of runway incursions are caused by pilot deviations, 19% are caused by vehicle/pedestrian deviations, and 21% of runway incursions are caused by controller operational errors. The incursion rate has grown fairly steadily from 0.3 incidents per 100,000 operations in 1988 to 0.64 in 2000.
Runway incursions most often occur when a pilot or ground vehicle operator either becomes disoriented or distracted and when the pilot or ground vehicle operator does not realize that the pilot or ground vehicle operator is about to enter an active runway. Conventional non-interactive airport signage does not provide any confirmation that the pilot/driver has arrived at the correct intersection, or any stop/go signal to let him know whether it is safe to proceed and that he is or is not authorized to do so. Noisy and congested radio frequencies or defective communications equipment sometimes results in important verbal ATC instructions being misunderstood or not heard at all. At large airports controllers are often overworked and do not have time to visually monitor the movement of all aircraft on the airport surface, and some incursions go undetected until a dangerous situation has been created. At night or in bad weather these problems are worsened by reduced visibility, which increases the probability of distraction or disorientation. Most large airports allow operations under Instrument Flight Rules (IFR) with visibilities as little as a quarter mile, conditions under which many aircraft on the ground will not even be visible from the tower. Thus, the controller is often forced to take the pilot's word for it that he is at the proper intersection. Many medium sized airports do not employ a separate ground controller at night, increasing the chances that an incursion can go undetected by an overworked tower controller distracted by simultaneous arriving aircraft, important phone calls, or other stressful circumstances. Finally, most of the recent conventional airport surface movement monitoring and signage systems that have been developed or proposed either utilize complex and expensive technologies (such as surface detection radar) or require disruptive excavation activities (for hardwired enhanced signage) during the installation process. These systems have therefore not been widely adopted because airport operators either cannot afford them or do not want to shut down all or part of the airport for installation.
The two greatest disadvantages of the conventional runway incursion prevention systems are the expense and disruptiveness of acquisition and installation of the equipment, plus the ambiguity and uncertainty introduced by the human interpretation factor associated with radar and enhanced vision systems. For example, the Airport Movement Area Safety System (AMASS) has no way of knowing the intent of an aircraft or vehicle approaching a runway from an intersecting taxiway, so the FAA turned off AMASS' warning capability for “side-impact” collision threats because the frequent nuisance alerts would have desensitized controllers to AMASS alerts). The FAA modified AMASS to look at single runways and ignore potential side-impact collisions. The Airport Surface Detection Equipment-Model X (ASDE-X) was intended to be a low-cost ground radar and warning system for medium-sized airports but appears now to have a lifecycle cost of about $13 million per unit. The Runway Status Light (RWSL) system is a system of lights automatically controlled through the use of surface radar data and is to be used in conjunction with surveillance data from Airport Surface Detection Equipment-Model 3 (ASDE-3) and other airport radar indicators. A prototype of the RWSL system was installed at Boston's Logan International Airport in 1995, and showed great promise but was cancelled possibly because the technology that was available at the time to control the light status was inadequate. The Runway Safety Monitor (RSM) provides single stage alerts; and the RSM requires software that derives three-dimensional invisible zones. Runway Incursion Prevention System (RIPS) requires updates to the ASD-B (Automated Dependent Surveillance-Broadcast) systems. RIPS is a component of NASA's AvSP (Aviation Safety Program)
Other conventional systems include the Synthetic Vision System (SVS) and the Hold Short Advisory Landing Technology (HSALT).
U.S. Pat. No. 6,168,294 describes an airport taxi signal light having a LED light array with light processing assembly and dichroic filter. U.S. Pat. No. 5,519,618 describes an airport surface safety logic, and U.S. Pat. No. 3,878,506 describes airport lighting and radar reflector combination. However, the technology described in these patents lack versatility.
Manufacturers of traditional airport taxiway lighting systems are Honeywell, Hali-Brite Inc., Raytech, Crouse Hinds, and OCEM. The Federal Aviation Administration and National Transportation Safety Board are useful government point of contacts for specification information regarding systems currently in use for runway incursion prevention. Aviation industry organizations that are interested in runway incursion prevention and airport improvement include the National Business Aircraft Association, Aircraft Owners and Pilots Association, and Airline Pilots Association.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a runway incursion detection system that is versatile. There is also a need for an airport surface movement monitoring and signage systems that works without interaction from a ground controller and that do not require complex and expensive technologies or disruptive excavation activities.
There is a also a need in the prior art for all-weather day/night aircraft/vehicle position monitoring, unambiguous pilot/operator signaling and warning, and low-cost non-disruptive facilities installation and operation that is provided by a system that is designed for simplicity, with no expensive ground radar stations or sophisticated software algorithms involved. There is also a need to reduce additional involvement from air traffic control personnel as well as to provide a portable and low cost runway incursion prevention system, in order to encourage widespread implementation of runway incursion detection systems and thus improve aircraft safety.